Food mixers typically comprise stand mixers, by which is meant the kind of kitchen machine in which a receptacle such as a mixing bowl is supported on a pedestal which also supports an electric motor and a drive system including a drive outlet, overhead of the bowl, which permits a planetary mixing action to be imparted to tools suspended into the bowl from the overhead drive outlet.
Food processors, on the other hand, typically comprise machines in which receptacles equipped with rotatable blades or the like can be driven from beneath by means of a motor and drive system housed within a casing upon which the receptacle is supported. Frequently such food processors present two drive outlets (sometimes these are disposed coaxially) which can selectively drive the blades or the like associated with different receptacles, such as a bowl and a goblet, for mixing and blending respectively.
Both types of such kitchen machines are extremely versatile, and recent technical developments provide the possibility of still broader operational capability; such arrangements including heating means provided to permit, in accordance with user selection, ingredients to be heated whilst being subjected to a mixing or processing action. The degree of heating employed may, in accordance with user selection, be sufficient to completely cook, to partially cook, or to merely warm ingredients and it will be understood in this respect that the degree of heating is influenced both by the heater power (wattage) used in any given situation and the time for which the heat is applied.
Such added operational facilities, whilst opening up various more sophisticated possibilities for food preparation, place increased demands upon the sensors and associated controls used to regulate the operation of such machines. In particular, there is a critical need, with kitchen machines equipped with heating capabilities, for accurate measurement of the temperature of the ingredients being mixed or processed and/or of a receptacle containing the ingredients, and it is one object of this invention to provide a kitchen machine incorporating rugged and accurate means for sensing the temperature of a receptacle and/or ingredients therein.